问题现象
使用 Yum 命令时遇到报错。
原因分析
由报错信息可知,在尝试从 CentOS 镜像列表获取信息时遇到了问题,无法解析 mirrorlist.centos.org 这个域名。这可能是由于网络连接问题导致的。
解决方案
1. 检查网络连接
首先通过 ping 命令检查网络连接,确保网络能够正常访问外网。
ping www.baidu.com
按 Ctrl + C 停止访问。若能正常访问,说明基础网络通畅。
2. 更换镜像源
如果网络正常,问题可能是当前的镜像源出现故障或者当前网络无法访问镜像源。可以尝试更换为其他可用的镜像源。
可以通过 vi 命令编辑 /etc/yum.repos.d/CentOS-Base.repo 文件,将其中的 mirrorlist 行用 # 号注释掉,并将 baseurl 行取消注释,并修改为其他可靠的镜像地址。
vi /etc/yum.repos.d/CentOS-Base.repo
建议将以下四个 baseurl 地址修改为阿里云的镜像地址:
baseurl=http://mirrors.aliyun.com/centos/$releasever/os/$basearch/
baseurl=http://mirrors.aliyun.com/centos/$releasever/updates/$basearch/
baseurl=http://mirrors.aliyun.com/centos/$releasever/extras/$basearch/
baseurl=http://mirrors.aliyun.com/centos/$releasever/centosplus/$basearch/
配置文件示例如下:
# CentOS-Base.repo
#
# The mirror system uses the connecting IP address of the client and the
# update status of each mirror to pick mirrors that are updated to and
# geographically close to the client. You should use this for CentOS updates
# unless you are manually picking other mirrors.
#
# If the mirrorlist= does not work for you, as a fall back you can try the
# remarked out baseurl= line instead.
#
[base]
name=CentOS-$releasever - Base
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=os&infra=$infra
baseurl=http://mirrors.aliyun.com/centos/$releasever/os/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
#released updates
[updates]
name=CentOS-$releasever - Updates
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=updates&infra=$infra
baseurl=http://mirrors.aliyun.com/centos/$releasever/updates/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
#additional packages that may be useful
[extras]
name=CentOS-$releasever - Extras
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=extras&infra=$infra
baseurl=http://mirrors.aliyun.com/centos/$releasever/extras/$basearch/
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
#additional packages that extend functionality of existing packages
[centosplus]
name=CentOS-$releasever - Plus
#mirrorlist=http://mirrorlist.centos.org/?release=$releasever&arch=$basearch&repo=centosplus&infra=$infra
baseurl=http://mirrors.aliyun.com/centos/$releasever/centosplus/$basearch/
gpgcheck=1
enabled=0
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
3. 检查 DNS 配置
如果还未解决,系统的 DNS 配置也可能有问题。可以尝试修改 /etc/resolv.conf 文件,添加可靠的 DNS 服务器地址,例如 8.8.8.8 和 8.8.4.4。
vi /etc/resolv.conf
nameserver 8.8.8.8
nameserver 8.8.4.4
修改完成后即可正常运行。


